<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
        /* 
        1.给受到float影响的元素clear:both;
        2.给他爹
         */
        .parent{
            width:200px;
            background:red;
            overflow: hidden;
        }
        .two{
            width:100px;
            height: 100px;
            background: blue;
            float: left;
        }
        .three{
            /* clear: both; */
            width:300px;
            height: 300px;
            background: green;
        }
    </style>
</head>
<body>
    <div class="parent">
        <div class="two">

        </div>
    </div>
    <div class="three">
         
    </div>
</body>
</html>